1. Field of the Invention
The present invention relates to a network resource provisioning method for bandwidth guarantee per flow, and more particularly, to a network resource provisioning method, which is a service quality guaranteeing method, for providing quality-guaranteed services by performing static provisioning based on existing requests for traffic to set an initial network and performing dynamic provisioning based on a change in incoming traffic during a data service, thereby guaranteeing bandwidth requested per flow, and a connection admission control method based on the network resource provisioning method.
2. Description of the Related Art
Advancements in data transmission technology have resulted in increases in the optical bandwidth of the Internet, e.g., XDSL and the Metro Ethernet. Also, the development of various Internet multimedia content has lead to the introduction of new application services, such as Internet broadcasting, Voice over IP (VoIP), and a virtual private network, which require guaranteed service quality. Accordingly, Internet service users have started requesting differentiated services to receive quality of service guaranteed per flow, and thus, much attention has been paid to the development of techniques of guaranteeing service quality on the Internet.
Accordingly, in the field of the Internet, there is a growing need for techniques of guaranteeing service quality that satisfy not only a bandwidth guarantee but also transmission reliability, real-time transmission, etc. in order to support service applications that need various requirements, not best-effort services.
Examples of techniques of guaranteeing service quality on the Internet include connection admission control, congestion control, traffic shaping/metering/marking, scheduling, etc. Among these techniques, connection admission control is first needed.
Connection admission control is aimed at provisioning network resources to provide a reliable path that guarantees users' requirements of a reduction in packet loss probability or network delays.
Methods of provisioning network resources using a bandwidth broker are broadly categorized into a static provisioning method and a dynamic provisioning method. Here, the bandwidth broker determines whether a user's request for a service is acceptable, and allocates resources in a network accordingly.
In general, the static provisioning method is used for network resource management using the bandwidth broker. In this method, resources are allocated to a predetermined routing path in units of a specific period of time (a day, a week, or a month) in an offline mode according to a service-level agreement, and when a user makes a request for a new connection, acceptance of the request is determined according to the allocated resources. Accordingly, the static provisioning method cannot exactly reflect the dynamic status of a network, resulting in inefficient use of resources.
In contrast, in the dynamic provisioning method, the bandwidth broker receives reports regarding the current status of a network from all nodes in the network and reflects the statuses in resource allocation. Thus, it is possible to dynamically manage resources and perform connection admission control when a user requests a new connection, according to the status of the network or a change in routing. However, this method needs frequent communication to be established between all of the nodes in the network and the bandwidth broker, and the bandwidth broker to perform resource management for each link in the network. Therefore, the dynamic provisioning method has disadvantages in terms of scalability and complexity.
Also, when using the bandwidth broker for resource allocation, since the bandwidth broker performs connection admission control for all requests for connection, responses to the requests cannot be immediately made and resource allocation depends greatly on the performance of the bandwidth broker.
Thus, the static provisioning method using a bandwidth broker is not applicable to dynamic Internet traffic or routing in a network, and a change in network resource allocation is made in units of a specific period of time in the static provisioning method, thereby preventing efficient use of network resources.
In the dynamic provisioning method, which has been introduced to compensate for the problems of the static provisioning method, the bandwidth broker receives reports regarding the status of a network from all nodes in the network and manages the network (even the levels of links in the network). Also, communication is frequently established between each node and the bandwidth broker, thereby preventing scalability and increasing complexity.